I am a middle Bucks County resident. While there may be a lack of mosques, there is also very few synagogues in the area as well. Rather than suspecting something sinister amongst the will of the people, or local government, I would instead assume there are not a significant enough number of residents practicing Judaism or Islam.
The area in which I live, and the people whom live here are very tolerant. We care not to have our character harshly judged by potential neighbors based solely on the number of mosques that have been built.